[TIMOB-5225] Slider change event object properties {x,y,globalPoint} are undefined

When the *change* event is fired on a Slider, the *x*, *y*, and *globalPoint* properties are being returned as undefined. Here is a simple example showing the bug, as well as a naive workaround that will allow you to ascertain the relative *x* position of the Slider using its width and current value. Obviously, this workaround only works with a slider whose range is from 0 to 1, but a more robust workaround could use the min and max ranges to create a 0 to 1 multiplier.

var win = Ti.UI.createWindow();
var slider = Ti.UI.createSlider();
slider.addEventListener('change', function(e) {
	Ti.API.info("x:" + e.x + " -- y:" + e.y + " -- globalPoint:" + e.globalPoint);
	Ti.API.info("calculated x:" + e.source.width * e.source.value);
});
win.add(slider);

win.open();